1 files changed, 132 insertions, 0 deletions
diff --git a/examples/Scheduler_example07_WDT/Scheduler_example07_WDT.ino b/examples/Scheduler_example07_WDT/Scheduler_example07_WDT.ino
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index 0000000..60983bd
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+++ b/examples/Scheduler_example07_WDT/Scheduler_example07_WDT.ino
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+/** 
+ *  TaskScheduler Test sketch - use of task IDs and watchdog timer to identify hung tasks
+ *  Test case: 
+ *    Watchdog timer is set to 2 seconds (interrupt + reset)
+ *    A hearbeat task (resetting the watchdog timer) is scheduled with 500 ms interval
+ *    A number of tasks are running every 1 second and "rolling the dice" 0..19.  If 5, task is made to enter infinite loop
+ *    Device should reset in 2 seconds after a task enters infinite loop
+ *    A task id and a control point number are saved to EEPROM prior to device reset, and are displayed after reboot.
+ *    In real life, device might chose to NOT activate certain tasks which failed previously (failed sensors for instance)
+ */
+
+#define _TASK_SLEEP_ON_IDLE_RUN
+#define _TASK_WDT_IDS
+#include <TaskScheduler.h>
+
+#include <EEPROM.h>
+#include <avr/wdt.h>
+
+Scheduler ts;
+
+// Callback methods prototypes
+void TaskCB(); 
+void HB(); bool HBOn(); void HBOff();
+
+// Three tasks emulating accidental infinite loop
+Task tTask1(TASK_SECOND, TASK_FOREVER, &TaskCB, &ts, true);
+Task tTask2(TASK_SECOND, TASK_FOREVER, &TaskCB, &ts, true);
+Task tTask3(TASK_SECOND, TASK_FOREVER, &TaskCB, &ts, true);
+
+// Heartbeat task - resetting the watchdog timer periodically
+// Initiates WDT on enable, and deactivates it on disable
+Task tHB(500, TASK_FOREVER, &HB, &ts, false, &HBOn, &HBOff);
+
+/**
+ * Emulating task callback function
+ *   Prints task id and randomly "hangs" in two places.
+ *   Control points are stored on the task prior to section which might hang,
+ *   making this information available to the WDT interrupt handler
+ */
+void TaskCB() {
+  Task& T = ts.currentTask();
+  
+  Serial.print("Task #:"); 
+  Serial.print(T.getId()); 
+  Serial.print(" current iteration = "); 
+  Serial.println(T.getRunCounter());
+
+// Hang if random number between 0 and 19 is 5 (5% probability)
+  T.setControlPoint(10);
+  if (random(20) == 5) for(;;);
+  
+// Hang if random number between 0 and 99 is more that 95 (5% probability)
+  T.setControlPoint(95);
+  if (random(100) > 94) for(;;);
+}
+
+/**
+ * This On Enable method sets up the WDT
+ * for interrupt and reset after 2 seconds
+ */
+bool HBOn() {
+  
+  //disable interrupts
+  cli();
+  //reset watchdog
+  wdt_reset();
+  //set up WDT interrupt
+  WDTCSR = (1<<WDCE)|(1<<WDE);
+  //Start watchdog timer with aDelay prescaller
+  WDTCSR = (1<<WDIE)|(1<<WDE)|(WDTO_2S & 0x2F);
+//  WDTCSR = (1<<WDIE)|(WDTO_2S & 0x2F);  // interrupt only without reset
+  //Enable global interrupts
+  sei();
+}
+
+/**
+ * This On Disable method disables WDT
+ */
+void HBOff() {
+  wdt_disable();
+}
+
+/**
+ * This is a periodic reset of WDT
+ */
+void HB() {
+  wdt_reset();
+
+}
+
+/**
+ * Watchdog timeout ISR
+ * 
+ */
+ISR(WDT_vect)
+{
+  Task& T = ts.currentTask();
+
+  digitalWrite(13, HIGH);
+  EEPROM.write(0, (byte)T.getId());
+  EEPROM.write(1, (byte)T.getControlPoint());
+  digitalWrite(13, LOW);
+}
+
+/**
+ * Standard arduino setup routine
+ */
+void setup() {
+  
+  Serial.begin(115200);
+
+  randomSeed(analogRead(0)+analogRead(5));
+  
+  pinMode(13, OUTPUT);
+  digitalWrite(13, LOW); 
+  
+ 
+  Serial.println("WDT heartbeat test");
+  Serial.print("Last task before reset="); Serial.println(EEPROM.read(0));
+  Serial.print("Last control point before reset="); Serial.println(EEPROM.read(1));
+  
+  delay(2000);
+
+  tHB.enableDelayed();
+}
+
+/**
+ * Not much is left for the loop()
+ */
+void loop() {
+  ts.execute();
+}
+\ No newline at end of file